Preventive and reverse effects of nifedipine on human bronchoconstriction "in vitro"

The effects of nifedipine, a calcium channel blocking agent, on human bronchoconstriction induced by acetylcholine and histamine were studied in vitro. Bronchial preparations were obtained from 13 patients undergoing surgery for bronchial carcinoma. Bronchial strips were mounted for continuous isometric tension recording. Acetylcholine and histamine caused bronchoconstrictions, but the constrictive effects were inhibited by 2.9 X 10(-6) M nifedipine. At a concentration of 2.9 X 10(-6) M nifedipine increased by 22-fold the concentration of acetylcholine required to produce a 50% of maximal contraction of bronchial strips, and by 160-fold the concentration of histamine required. Nifedipine also reversed already established bronchoconstrictions by acetylcholine and histamine. The percentage of contraction at 20 min after 2.9 X 10(-6) M nifedipine was 7 +/- 11.1% (mean +/- SEM) and - 21 +/- 20.0% of the control maximal response by 10(-3) M acetylcholine and 10(-3) M histamine, respectively. Thus, nifedipine clearly prevented and reversed pharmacologically-induced bronchoconstriction in humans. These results suggest that it is valuable to administer nifedipine to prevent and treat asthma attack.

Vesicocolic fistula formed by "collision" tumor between transitional cell carcinoma of urinary bladder and adenocarcinoma of the sigmoid colon

A patient with vesicosigmoid fistula due to "collision" tumor between adenocarcinoma of the sigmoid colon and transitional cell carcinoma of the urinary bladder is presented. Resection of the sigmoid colon and partial cystectomy were performed. The clinical symptoms, diagnostic procedures and treatments are discussed.

Noxious stimuli and Met-enkephalin release from nucleus reticularis gigantocellularis

The nucleus reticularis gigantocellularis of the rat medulla oblongata was perfused in situ, and effects of noxious stimuli on the release of immunoreactive Met-enkephalin were examined. Formalin-induced and thermal but not mechanical stimuli increased the "tonic" release of immunoreactive Met-enkephalin from this nucleus. No "phasic" increase was observed following the three forms of stimulation. A topical application of dibucaine abolished the formalin-induced increase in the release of immunoreactive Met-enkephalin. Therefore, the possibility that persistent noxious stimuli may activate the Met-enkephalin-containing fibers in the nucleus reticularis gigantocellularis has to be given consideration.

Studies on precursor proteins PIVKA-II, -IX, and -X in the plasma of patients with 'hemorrhagic disease of the newborn'

Factors II, IX, and X in the plasmas of 10 patients with 'hemorrhagic disease of the newborn' were investigated by means of electroimmunoassay and crossed immunoelectrophoresis (CIE). The biological activity was within 4.2-30 U/dl for factor II, 5.1-20 U/dl for factor IX, and 5.2-24 U/dl for factor X, whereas the immunological antigen was within 33-58, 25-50, and 35-60 U/dl, respectively. Thus, for all factors, 1.7 times more antigen than activity was present. The CIE pattern of factors II and IX in the presence of Ca++ ions clearly showed a biphasic precipitin arc, and in the absence of Ca++ ions, only one precipitin arc was observed. These results implied the presence of precursor proteins PIVKA-II and -IX in the plasma. However, even in the presence of Ca++ ions the CIE pattern of factor X antigen in the patient plasmas only showed a single precipitin arc with a slightly faster than normal electrophoretic mobility. PIVKA-II, -IX, and the abnormal factor X antigen (PIVKA-X) disappeared within 24 h after the patients were treated with vitamin K.

[Thyroxine deiodination in the fetus]

T4 deiodination has been studied using the fetal liver and kidney of miniature goats during late pregnancy. They were homogenized in 0.15M phosphate buffer, pH7.4 to make 25% homogenate which was incubated with outer ring labeled 125I-T4, 125I-rT3 or inner ring labeled 125I-T4 at 37 degrees C for 15, 30, 60, 90 or 120 min. either with or without 20mM DTT. After incubation they were extracted in ethanol and subjected to TLC to separate 125I-compounds. The radioactivity of each compound was measured and its production rate was expressed as a percentage of total radioactivity of the extract. The activity of deiodination in the outer ring of T4 in fetal liver was similar to that observed in the mother's . Fetal kidney showed a markedly increased activity in deiodination in the inner ring compared to that of all the other tissues studied. In contrast it showed the lowest deiodination in the outer ring. The addition of 20mM DTT had little effect on T4 deiodination in fetal organs. These data indicate a significant difference between T4 deiodinating activity in the liver and kidney of the fetus. It is felt that the kidney plays a more important role in T4 deiodination than the liver during fetal life.

Asymmetric (differential) cell division of thymic lymphocytes by means of cytoplasmic polarization: possible biological meanings

A series of morphological studies at the light- and electron-microscopical levels have led to the conclusion that a significant proportion of immature thymic lymphocytes would undergo asymmetric (differential) cell division: at the telophase of such dividing cells one of two daughter cells retains morphological characteristics very similar to those of its parent cell, whereas the counterpart daughter cell looks much differentiated. Polarization of the cytoplasm is considered to be the mechanism whereby the asymmetry is generated. The phenomenon is observable in both prenatal and postnatal life of all the animal species examined, that is chicken, guinea pig, rat and mouse, meaning that it is a general phenomenon among the animals possessing the thymus. The frequency of asymmetrically-dividing cells is relatively high in large-sized cell fractions (more than 40% of total dividing cells). The conclusions leading from the above-mentioned morphological studies are supported by the cell kinetic studies performed by Metcalf in the mid-1960s. Asymmetric cell division may be primarily involved in the maintenance of immature 'stem cells' while concomitantly producing differentiated cells of smaller sizes. The phenomenon might also play an important role in the differentiation of thymocytes into distinct lineage of thymic lymphocytes such as cortex and medulla lymphocytes. Furthermore, the present findings raises the idea that hematopoietic cells including lymphoid cells would possess, in general, intracellular mechanisms to undergo asymmetric cell division.

Effect of Bordetella pertussis leukocytosis (lymphocytosis)-promoting factor (LPF) on the physical lymphoepithelial-cell association studied with the use of an in vitro model of mouse thymus

The effect of highly purified leukocytosis (lymphocytosis)-promoting factor (LPF) of Bordetella pertussis on physical lymphocyte and reticuloepithelial (RE) cell association was studied in an in vitro thymus model. First, a simplified in vitro system to assess the lympho-RE-cell association was developed. A completely confluent layer of thymic RE cells was formed by cultivating trypsinized thymus cell suspensions from 2- to 7-day-old mice. When thymic lymphoid cells were seeded on this cell layer and cultivated overnight, a significant proportion of them were found underneath the RE cell layer. This physical lympho-RE-cell association was quantitated by counting the lymphoid cells underneath the RE cell layers. Second, the effect of LPF on this physical lympho-RE-cell association phenomenon was investigated. Addition of LPF to the culture markedly inhibited the formation of the lympho-RE-cell complex; that is, it inhibited the infiltration of lymphoid cells under the RE cell layer. LPF rendered a nearly maximal level of inhibitory effect at a dose of 0.1 ng/ml. Furthermore, LPF enhanced the liberation of lymphoid cells from preformed lympho-RE-cell complexes. On the other hand, LPF had no direct cytotoxic effect on lymphoid cells at doses below 1 microgram/ml. In order to investigate whether LPF produced the effect by acting on lymphoid cells, RE cells, or both, the following experiments were performed. When lymphoid cells were pretreated with LPF and added to normal RE cell layers, the lympho-RE-cell association was maximally inhibited above the dose of 1 ng/ml. Treatment of these LPF-treated lymphoid cells with anti-LPF antibodies failed to abrogate the effect of LPF. When RE cell layers were similarly pretreated with LPF and were cultivated with normal lymphoid cells, however, much higher doses of LPF, above 100 ng/ml, were required for maximal inhibition. Furthermore, treatment of these LPF-treated RE cells with anti-LPF antibodies abrogated the effect of LPF. Therefore, the apparent effect of LPF on RE cells was considered to be due to the carry-over by RE cells of LPF, which should directly act on lymphoid cells at extremely low doses. On the basis of these results, it was concluded that LPF acted directly on lymphoid cells without mediation of RE cells. These in vitro results appear to parallel the effects of LPF in vivo, where it induces a depletion of cells in the thymus. The model may be useful to study this phenomenon and the concomitant accumulation of blood lymphocytes.

Effect of Bordetella pertussis leukocytosis (lymphocytosis)-promoting factor (LPF) on the physical lymphoepithelial-cell association studied with the use of an in vitro model of mouse thymus

The effect of highly purified leukocytosis (lymphocytosis)-promoting factor (LPF) of Bordetella pertussis on physical lymphocyte and reticuloepithelial (RE) cell association was studied in an in vitro thymus model. First, a simplified in vitro system to assess the lympho-RE-cell association was developed. A completely confluent layer of thymic RE cells was formed by cultivating trypsinized thymus cell suspensions from 2- to 7-day-old mice. When thymic lymphoid cells were seeded on this cell layer and cultivated overnight, a significant proportion of them were found underneath the RE cell layer. This physical lympho-RE-cell association was quantitated by counting the lymphoid cells underneath the RE cell layers. Second, the effect of LPF on this physical lympho-RE-cell association phenomenon was investigated. Addition of LPF to the culture markedly inhibited the formation of the lympho-RE-cell complex; that is, it inhibited the infiltration of lymphoid cells under the RE cell layer. LPF rendered a nearly maximal level of inhibitory effect at a dose of 0.1 ng/ml. Furthermore, LPF enhanced the liberation of lymphoid cells from preformed lympho-RE-cell complexes. On the other hand, LPF had no direct cytotoxic effect on lymphoid cells at doses below 1 microgram/ml. In order to investigate whether LPF produced the effect by acting on lymphoid cells, RE cells, or both, the following experiments were performed. When lymphoid cells were pretreated with LPF and added to normal RE cell layers, the lympho-RE-cell association was maximally inhibited above the dose of 1 ng/ml. Treatment of these LPF-treated lymphoid cells with anti-LPF antibodies failed to abrogate the effect of LPF. When RE cell layers were similarly pretreated with LPF and were cultivated with normal lymphoid cells, however, much higher doses of LPF, above 100 ng/ml, were required for maximal inhibition. Furthermore, treatment of these LPF-treated RE cells with anti-LPF antibodies abrogated the effect of LPF. Therefore, the apparent effect of LPF on RE cells was considered to be due to the carry-over by RE cells of LPF, which should directly act on lymphoid cells at extremely low doses. On the basis of these results, it was concluded that LPF acted directly on lymphoid cells without mediation of RE cells. These in vitro results appear to parallel the effects of LPF in vivo, where it induces a depletion of cells in the thymus. The model may be useful to study this phenomenon and the concomitant accumulation of blood lymphocytes.